It was football worthy of a grander stage, as not even the uneven pitch could ruin this spectacle, as it did at Wembley at the weekend.
Goals from Sam Saunders, Mark Arber and a contender for goal of the season from Solomon Taiwo sealed the points which take the Daggers up to seventh.
Dagenham dominated the early phases and they got their just rewards in the 20th minute. Paul Benson brought the ball down brilliantly on the edge of the area before nudging it to the on-rushing Saunders, whose precise first-time shot found the far corner.
The Daggers were rampant and Ben Strevens almost doubled their lead with an audacious attempt from the by-line, but Ryan Dickson came to the rescue for Brentford.
The Bees almost equalised when Marcus Bean was afforded the chance to shoot after Arber's miscued interception, but David Button was up to the task.
The hosts responded to the scare in perfect fashion, as midfielder Taiwo collected a clearance on the edge of the box, before unleashing an unstoppable volley past Ben Hamer into the bottom corner.
The high octane action continued after the break and it didn't take long for the third to arrive. Inevitably, Saunders was the architect, swinging a deep corner that looped over the head of Hamer and found Arber lurking at the back post for a simple header.
Such a shame that the audience at home were denied such thrilling entertainment, after the power failure that caused the postponement of this fixture last month.
The Bees scored a consolation through Damian Spencer, but it was too little, too late.
In an ironic twist, the floodlights failed seconds after the final whistle. Truly, non-stop drama to the very end.